5of5The Russ Building, designed by George Kelham, was San Francisco's tallest tower at 435 feet when it opened in 1927. More than two dozen rivals have passed it since then, but it remains one of the best skyscrapers in the city.Photo: John King

The cultural reference that makes you feel ancient is the one that you throw into a conversation and it sinks like a lead-encased stone.

I was leading a group of college students on a walk through the third level of the Embarcadero Center, ghostly calm on a Saturday afternoon, explaining how this once was a sizzling scene where the after-work crowd would connect in, you know, fern bars and the like.

They had absolutely no idea what I was talking about. So much for the late 1970s and early 1980s, Huey Lewis and angel-hair pasta; score one instead for the fact that no matter how often we build the city of tomorrow, future generations have a way of leaving it behind.

Blank stares aside, it was great to spend an afternoon exploring downtown San Francisco’s procession of landscapes that bear witness to the expectations of their moment. Most of the students were majoring in urban studies at UC Berkeley’s College of Environmental Design, interested less in architecture than the vagaries of trying to arrange buildings and streets so that they’ll fit together in the moment and flourish long-term.

We started at the Montgomery BART Station, then headed north to the Transamerica Pyramid and hooked through Jackson Square to Golden Gateway, down through Embarcadero Center and across Market Street to the blocks where the Transbay Transit Center is rising piece by cross-braced piece.

Montgomery Street is the Big City of yore, masonry embellished with columns and medallions, robust shafts pushed tight to the street and soaring straight to the sky. Some days, I half-expect to see Clark Kent step into a phone booth, emerging as Superman to leap those tall buildings in a single bound.

Golden Gateway, by contrast, is San Francisco’s purest vision of postwar urban renewal: high-rise apartments on podiums across from grassy Sydney Walton Square, rippled with hillocks and dotted with modern art of the 1960s. In its own way it’s as quiet as suburbia — and that was the idea, for this was housing intended to compete with the spacious housing tracts then spilling down the Peninsula and across the East Bay. The challenge wasn’t to house all the people who wanted to make San Francisco their home; it was how to keep San Franciscans of the 1950s and ’60s from moving to greener pastures.

The passage from Golden Gateway to Embarcadero Center was easy enough; sky bridges extend across streets, traffic lanes below, a way for workers and residents to reach their destinations without worrying about crosswalks or careless drivers or automobile exhaust (remember when cars belched lead-dark fumes? Oh wait, probably you don’t). And when we stepped into the central atrium of the Hyatt Regency, designed by John Portman amid the societal tumult of the late 1960s and early 1970s, a whole new tomorrowland burst forth: the city as sci-fi spectacle, separated from street life not just for convenience but for fear of what might be outside.

None of the students had been inside the 15-story space, with its pyramid-shaped void and glass elevators humming up into the gloom of ever-closer concrete walls and walkways. Some thought it was dystopian cool; others thought it was dystopian grim. There was a similar split on the notion of open-air skywalks as a pedestrian circulation network: The sterility put off the students, but the ease had a certain convenient allure.

Differences of opinion aside, the sense of discovery was shared. Yesterday’s corporate landscape is today’s Bizarro World, a realm as exotic as the 19th century collage of buildings and alleys in Jackson Square that were rediscovered and restored by urban pioneers even as master-planned modernism seemed to hold sway.

When we crossed Market and walked along Mission Street, amid cranes and construction sites and glass-walled towers with pedestrian plazas at their base, I asked the students what they thought about the tactile difference between this sleek world and the masonry walls of the old Financial District. If the atmospheric richness of Montgomery Street had its fans — and it did — others appreciated the lightness of the new buildings, the way that some even send sun ricocheting to the ground.

There’s no grand moral to all this. But there is a gentle reality check. Absolute truths — the platitudes you hear at City Hall from development fans and foes — should be taken with a grain of salt.

Public debates over neighborhoods or skylines or architectural styles tend to be strident and self-serving. Every loud faction stakes out its position as an absolute, the civic truth for now and evermore.

What gets lost is the shift of generations, of cultures, of the way we view our surroundings as we acclimate to change. The shock of the new becomes the familiar scene to which we return home.

What will tomorrow’s urban residents make of what we hand off to them? All I know is this: They aren’t likely to be discussing the topic in that hot new fern bar.

Place appears on Wednesdays. John King is The San Francisco Chronicle’s urban design critic. E-mail: jking@sfchronicle.com Twitter: @johnkingsfchron

John King is The San Francisco Chronicle’s urban design critic, taking stock of everything from Salesforce Tower to public spaces and homeless navigation centers. A two-time Pulitzer Prize finalist and author of two books on San Francisco architecture, King joined The Chronicle in 1992 and covered City Hall before creating his current post in 2001. He spent the spring of 2018 as a Mellon Fellow in Urban Landscape Studies at Dumbarton Oaks in Washington, D.C.